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S. B. Howell (WIYN/NOAO), T. E. Harrison, R. Campbell (NMSU)
We have obtained R~2000 IR spectra from the IRTF, and Keck II of more than ten secondary stars in cataclysmic variables in the orbital period range of 3-4 hours. This orbital period range is of great interest as it contains cataclysmic variables that evolved from longer period and should contain the most thermally bloated, non-equilibrium secondary stars. Additionally, some CVs form in this period range and should contain essentially normal main sequence secondaries. Few of our secondary stars appear to be normal main sequence stars in terms of their apparent abundances and thus may be indicators of systems evolved from longer orbital periods. Their observed abundance patterns are generally consistent with CNO processed material but other oddities are seen.. Two systems, the odd dwarf nova IP Peg and the polar AM Her, appear to contain completely normal secondary stars possibly indicative of their recent formation in this orbital period range. We explore the properties observed with IR spectroscopy and photometry and relate the results to detailed binary evolution models for CVs in this period range.
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Bulletin of the American Astronomical Society, 36 5
© 2004. The American Astronomical Society.